The news comes comes in the wake of a call by former University of Limerick president Dr Ed Walsh for Mr Ahern's state car to be taken off him -- due to his decision to be filmed in a cupboard for a newspaper TV ad.

Mr Ahern has also been criticised by the opposition parties for using his state car to travel to signings of his recently published biography.

According to new figures from the Department of Justice, the cost of fuel and maintenance for the state cars of Mr Ahern and the four other surviving ex-Taoisigh came to €33,867 last year -- an average of €6,773 each. When the average €77,000 salary of a garda driver is added in, it brings the cost of Mr Ahern's state car to around €84,000 annually.

The figures also show that Mr Ahern has a total of 186,450km clocked up on his Mercedes S350. The Department of Justice was not able to confirm last night if this was the same Mercedes S350 he was given in 2006 when he was Taoiseach.

The department said state cars were provided to all ex-Taoisigh and former Presidents "pursuant to a long-standing arrangement".

However, the cost of providing luxury cars with garda drivers for ministers and former Taoisigh has now reached €5m a year. The 26-car ministerial fleet includes seven Mercedes, seven Audi A6s, three BMW 5 Series, four Lexus cars, two Toyota Prius hybrids, two Fords and one Citroen C6.

The figures obtained by Fine Gael TD Simon Coveney show the average cost of providing each car was around €195,000 when fuel, depreciation and garda salary costs were included. He said the annual cost of the state car fleet had to be reduced.

"Ireland is a country under massive financial pressure," he said. "We simply can't afford those kind of luxuries," he said.

The garda salary costs account for 84pc of the bill. There are around 54 garda state car drivers operating on a week-on/week-off roster. They were paid €4.2m in wages last year -- an average of €77,000 each.

Former Taoiseach Albert Reynolds has the state car with the more mileage on the clock than anyone else. He has a 2005 Mercedes E240 which now has 307,000km on the clock.

Among other former taoisigh, Garret Fitzgerald has around 45,000km on his state car (a 2004 SAAB 95SE model), Liam Cosgrave has around 102,000km on his 2006 Ford Mondeo Ghia, and John Bruton has around 200,000km in his state car.